Assassin’s Creed 3 has a "Wolf Pack" mode that supports four online players. There is no local/split split screen/couch co-op.

Can the Assassin’s Creed 3 campaign be played cooperatively?

No. The cooperative Wolf Pack mode is separate from the campaign.

How many players can play Assassin’s Creed 3 in online co-op?

Assassin’s Creed 3 supports four player online co-op.

How do you begin a co-op session?

The Wolf Pack mode can be found under the multiplayer options.

What are the different game types in Wolf Pack mode?

Matched can be set to private or open. Private matches have three difficulty settings. Open matches have a locked difficulty.

Can I drop in or out of a game in progress game?

Yes, you can drop in and out of random games in progress. You cannot be invited to a friend's game in-progress.

Is there public matchmaking in the Wolf Pack mode?

Yes.

How does game progress work?

Wolf Pack mode uses the same profile and information as the multiplayer versus game. You can rank up and unlock new abilities and customization options. This progress is reflected in both the multiplayer modes and the co-op mode.

Do enemies scale based on the number of players?

Yes. The number of target AI players is directly related to the amount of human players.

Can I play privately, solo, or with less than four players?

Yes, you can play solo or with two or three other players. The game will scale down the AI players.

What about Playground mode?

This is an open mode where up to four players can learn level layouts while assassinating assigned targets. There is no scoring in Playground mode.